1. Field of the Invention
The present invention relates generally to the field of hand tools, and more particularly to a tool hand tool for the removal of a hinge pin from a door hinge assembly.
2. Background Discussion
Various inventions have been previously disclosed for hinge pin removal tools, and combination tools having a hinge pin removal feature. Many of the previous inventions that disclose hinge pin removal apparatus cause hinge or door damage, require undesirable strong impact concussion forces, or have insufficient leverage to first free, and then remove the hinge pin easily from its parent hinge assembly.
The present invention provides a tool hinge pin removal tool having the capability for producing a strong increase in mechanical advantage force to effect the hinge pin extraction by a housing block assembly having an internal gear train subassembly, combined with a cooperating pry head subassembly mechanism, and a positional retaining ring, the housing block assembly component members cooperating together to thus obtain a stronger extracting mechanical force than the previous hinge pin removal methods and devices.
Such previous U.S. Patents include U.S. Pat. Nos. 5,896,607, 6,256,855, 6,298,512, and 6,351,881.
U.S. Pat. No. 5,896,607 discloses a multi-purpose hinge pin remover with a hand guard, which can be used as a pry bar. The multi-purpose hinge pin remover has a hand guard, a hammer head, and two additional working surfaces for repairing shingles.
U.S. Pat. No. 6,256,855 discloses a tool for removing a hinge pin from a hinge assembly to facilitate the removal of doors. It comprises a pair of plier members, each with a jaw portion and a handle portion. The jaws of the plier member are made to fit around the shaft of a hinge pin where a force is applied in the removal of the hinge pin.
U.S. Pat. No. 6,298,512 discloses the same hinge pin remover with a hand guard as in U.S. Pat. No. 5,896,607. However, it has the two new additions: a pry ridge added to the V-pry bar, and a threaded hole to receive a variety of work tools. This multi-purpose hinge pin and plastic clip remover comprises a bar shape with a claw having a V-shaped pry bar with a top surface designed to fit under a plastic cap.
U.S. Pat. No. 6,351,881 discloses a hinge pin remover with a head, a distal end; and a cylindrical stem portion. It comprises a bar portion with a first and second end portion. The first end portion has a flat tip with a concavely curved edge used to insert between the head of a hinge pin and a hinge to wedge the hinge pin and hinge apart. The second end portion consists of a cylindrical projection used as a handle to displace the pin from the hinge plate.
These and other prior art U.S. Patents are hinge damage prone because they require the application of the brute force of a hammer impact in combination with a prying screwdriver or chisel applied to the front undershoulder of the hinge pin, or are ineffectual because they fail to apply sufficient mechanical force to remove the hinge pin from its hinge assembly.
A hinge pin removal tool is disclosed comprising a housing block assembly containing subassembly component members including a housing block subassembly, an internal gear train subassembly, which when the gear train subassembly is activated, a moveable pry head subassembly mechanism attached to the gear train subassembly, moves in parallel relationship vertically upward, causing the pry head subassembly mechanism, horizontal jaw face end section having a disc-beveled pry wedge surface to press against, into, and then under the hinge pin front undershoulder that is held against and between the retention contact combination of the front face groove of the housing block, the disc-beveled pry wedge surfaced, of the jaw face end section of the pry head subassembly mechanism, and the beveled inner diameter of the retaining positional ring extending outward from the housing block subassembly. The housing block subassembly is fabricated with a semi-circular, vertically grooved, front face surface for longitudinally facing, containing and exerting a base pressure on the front surface of the hinge pin barrel housing of the hinge assembly, and further contains a horizontally protruding, retaining positional ring mounted on the housing block front face upper surface to locate and position for extraction the hinge pin shoulderhead with respect to and in proper relationship with the jaw face end section, disc-beveled pry wedge surface, of the hinge pin removal tool. The gear train has a drive gear shaft extension protruding backward and outward from its central longitudinal axis, which when rotated, drives the gear train to move its mating rack gear base bar vertically upward, where it transmits a like vertical, parallel upward force to a connecting rod attached to the pry head subassembly mechanism, screw tail end section, and also to the disc-beveled pry wedge surface, jaw face end section, that has been pre-positioned to press against and under the hinge pin front undershoulder, for moving and urging the hinge pin vertically upward, and thereby, displacing the hinge pin from the hinge assembly.
An object of the present invention is to provide a hinge pin removal tool with the high mechanical advantage force needed to efficiently and simply remove the hinge pin from the hinge assembly without damage to nearby surfaces.
Another object of the present invention is to provide a hinge pin removal tool that does not require the application of high concussion force, such as a hammer.
Another object of the present invention is to provide a hinge pin removal tool employing the high mechanical advantage of a gear train.